Evaluation of Bromadiolone Against House Mouse (Mus Domesticus) Populations in Irrigated Soybean Crops. Ii. Economics.

Abstract

The economics of controlling house mice [M. musculus] using 0.005% bromadiolone-treated wheat placed in bait stations within soyabean crops was evaluated in New South Wales during 1989 when mouse densities were approx. 200-300/ha. Damage by mice to soyabean crops was assessed up to 200 m into 2 crops (1 with bait and 1 without) on each of 2 farms just before baiting, and 22 and 42 d after baiting. Mouse damage in each crop was always <10%, and was greatest in patches of high crop density. Damage was similar at the crop perimeters and up to 100 m into the crops, but 200 m from crop perimeters, damage was less prevalent. By 42 d after baiting, the differences in crop losses relative to pre-baiting damage levels were minimal. Estimates of losses caused by mice in 3 of the principal soyabean growing regions of New South Wales were obtained from all farmers who grew soyabeans in 1988-89. The combined losses caused by mice to growers in these regions in 1989 was about $A2 million.